Acute cardiac ischemia in patients with cocaine-associated complaints: results of a multicenter trial.

STUDY OBJECTIVE: To describe the characteristics of a large group of patients who presented to emergency departments with cocaine-associated symptoms consistent with acute cardiac ischemia (ACI) and to determine the incidence of confirmed ACI including acute myocardial infarction (AMI) in this population.

METHODS: We performed a substudy on all patients in a multicenter prospective clinical trial (the Acute Cardiac Ischemia-Time Insensitive Predictive Instrument [ACI-TIPI] Clinical Trial) that enrolled ED patients with chest pain or other symptoms consistent with ACI including subjects with identified cocaine use. Demographic and clinical features, including initial and follow-up clinical data, ECGs, and tests to determine serum creatine kinase isoenzyme MB subunit concentrations, were analyzed. Diagnoses of AMI followed the World Health Organization criteria for AMI and of angina pectoris, the Canadian Cardiovascular Society Classification.

RESULTS: Of the 10,689 patients enrolled in the trial, 293 (2.7%) had cocaine-associated complaints. Among the 10 participating hospitals, the incidence of patients with cocaine-associated symptoms varied from 0.3% to 8.4%. Only 6 patients (2.0%, 95% confidence interval [CI] 0.76% to 4.4%) had a diagnosis of ACI; 4 (1.4%, 95% CI 0.37% to 3.5%) had unstable angina, and 2 (0.7%, 95% CI 0.08% to 2.4%) had AMI. Although patients with cocaine-induced complaints were as likely to be admitted to the coronary care unit compared with all study patients without cocaine use (14% versus 18%, P =.14, difference not significant), these patients were much less likely to have confirmed unstable angina (1.4% versus 9.3%, P <.001) or AMI (0. 7% versus 8.6%, P <.001). Compared with patients younger than 45 years, patients with cocaine usage were more likely to be admitted to the ICU (14% versus 8.0%, P =.0018) but less likely to have confirmed AMI (0.7% versus 2.8%, P =.033).

CONCLUSION: Patients presenting to EDs with cocaine-associated chest pain or related symptoms infrequently had ACI, and even less so, AMI. This suggests the need for selectivity in the hospitalization of patients with such cocaine-associated symptoms.